Passengers reported that Abdulmutallab was calm and lucid throughout.  One flight attendant asked him what he had had in his pocket, and he replied “explosive device.”    (In his pocket???  What if he said "Electronic Device?")

These prosecutions are being handled by the U.S. Attorney’s Office for the Eastern District of Michigan, with assistance from the Counterterrorism Section of the Justice Department’s National Security Division.

The investigation is being conducted by the Federal Bureau of Investigation, US Customs and Border Protection, and the Joint Terrorism Task Force.

http://knucklz.com/2009/12/26/terrorist-plane-threat-seems-hokey.aspx

One CNN Report:

Could it be possible that the government and media are jumping to an embarrassing conclusion, along  with potential  racial profiling here?  I am an electrical engineer by profession for over 30 years, and the description of the explosion sounds just like a faulty battery on a personal electronic device (PED).  If the plane was just starting it's descent, it could be he was stowing his device at the time of the explosion (turning it on/off, cabin pressure fluctuations, etc.), a more likely time for the battery to explode if it were faulty. These PED battery explosions are typically  "small" and limited in area, consistent with the reported events. 

 

 

POTENTIAL FOR IN-FLIGHT FIRES DUE TO LITHIUM BATTERY FAILURE

INTRODUCTION

The purpose of this Commercial and Business Aviation Advisory Circular (CBAAC) is to alert air operators of the potential for in-flight fires caused by the failure of lithium ion and lithium batteries contained in portable laptop computers and other portable electronic devices. 

http://www.tc.gc.ca/civilaviation/commerce/circulars/ac0260.htm